docs: def rsa_encrypt_key_base64_encoded(rsaprivatekey, rsapublickey, plainkey):
      # type: (cryptography.hazmat.primitives.asymmetric.rsa.RSAPrivateKey,
      #        cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicKey,
      #        bytes) -> str
      """Encrypt a plaintext key using RSA and PKCS1_OAEP padding
      :param rsaprivatekey: RSA private key
      :type rsaprivatekey:
          cryptography.hazmat.primitives.asymmetric.rsa.RSAPrivateKey
      :param rsapublickey: RSA public key
      :type rsapublickey:
          cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicKey
      :param bytes plainkey: plain key
      :rtype: str
      :return: encrypted key
      """
      if rsapublickey is None:
          rsapublickey = rsaprivatekey.public_key()
      enckey = rsapublickey.encrypt(
          plainkey, cryptography.hazmat.primitives.asymmetric.padding.OAEP(
              mgf=cryptography.hazmat.primitives.asymmetric.padding.MGF1(
                  algorithm=cryptography.hazmat.primitives.hashes.SHA1()),
              algorithm=cryptography.hazmat.primitives.hashes.SHA1(),
              label=None))
      return blobxfer.util.base64_encode_as_string(enckey)